Metal matrix composites (MMCS) refer to a class of composite materials in which one constituent is a metal or alloy, and another constituent is a reinforcement. Such material is capable of being fabricated into a variety of components having improved properties such as the strength characteristics of steel (e.g., increased stiffness, enhanced fatigue strength, improved wear resistance, etc.) at a fraction of the weight. Such properties also include excellent performance at high temperatures (e.g., durability with an extremely low co-efficient of thermal expansion), the absence of out gassing and high electrical conductivity, among others.
Accordingly, such material has found its way into a variety of practical applications. For example, manufacturers have used MMC material to fabricate electronic heat sinks, automotive components (e.g., drive shafts, push rods, brake rotors, etc), aircraft components (e.g., fins, nozzles, washers, etc.) and electronic components (e.g., composite conductors, electronic packaging elements, etc.).
One conventional powder metal (PM) fabrication process includes a compaction step, a sintering step and a coining step. In the compaction step, a manufacturer cold presses the MMC material into what is commonly referred to a green compact having the general shape of the end result component. In the sintering step, the manufacturer heats the green compact to a temperature that is just under the melting temperature of the metal constituent in order to metallurgically bond grains within the green compact together and thus consolidate the compact into a reduced structure. In the coining step, the manufacturer re-presses the structure to provide higher precision finishing for the component.